Here's why Honey Nut Cheerios pulled its mascot

(CNN) -- In a stark reminder that the world's population of bees is plummeting, Cheerios pulled its mascot, Buzz the Bee off the box of Honey Nut Cheerios.

Bees play a critical role by pollinating 35% of the world's food supply. The fate of many species and billions of dollars of global crops ride on their tiny backs.

But bee colonies are collapsing around the world as parasites, pesticides and habitat loss take a deadly toll. For the first time this year, a bee species in the US was declared endangered by the US Fish and Wildlife Service.

"Buzz is missing because there's something serious going on with the world's bees. Bee populations everywhere have been declining at an alarming rate, and that includes honeybees like Buzz," Cheerios posted.

Cheerios launched a campaign called #BringBacktheBees to send 100 million free packets of wildflower seeds.

The company is encouraging people to plant the seeds and post pictures of what springs from the ground on social media.

Wildflowers create bee-friendly habitats where they can collect pollen and nectar, and feed their young.

Bees have been losing their flower-rich homes in recent decades.

There are a number of reasons for the crash of pollinator bees worldwide. Mainly, those are habitat loss (nearly 40% of all land is used for agriculture, according to the Food and Agriculture Organization), climate change (the land that's left is changing, and this is shrinking the ranges of some bees) and rampant chemical use.